Drilling rigs supported by floating drill ships or floating platforms are often used for offshore well development. These rigs present a problem for the rig operators in that ocean waves and tidal forces cause the drilling rig to rise and fall with respect to the sea floor and the subterranean well. This vertical motion must be either controlled or compensated while operating the well. Without compensation, such vertical movement may transmit undesirable axial loads on the rigid tubular strings that extended downwardly from the drilling rig. This problem becomes particularly acute in well operations involving fixed bottom hole assemblies, such as packers.
For example, once a lower completion has been installed in a casing string or open hole location, it is common to stab the lower end of the upper completion, run into the well on a tubing string, into the packer at the top of the lower completion assembly. Typically, the connection operation requires that the tubing string apply a predetermined amount of axial and/or rotational force against the packer. Once connected, any vertical movement from the ship or platform will create undesirable downward and upward forces on the packer or may cause premature actuation and/or failure of components.
During the installation process, a travel joint in the tubing string may be used to allow for telescopic extension and contraction of the tubing string. Typically, the travel joint is run downhole in a locked position, then unlocked once the tubing string is connected to the packer. Various forces may result in the unlocking of the travel joint during conveyance and installation, which is to say before the travel joint is coupled to the packer. Once unlocked, it is virtually impossible to sting into the packer without relocking the travel joint, which may require an additional trip out of the well to redress the travel joint.